Serial Ports
2008
 |
 Digi Neo Serial adapter PCIe RS 232 4 ports 77000890  US $251.99
|
 STARTECHCOM 10PKPCI2S550 10pk 2 Port Serial PCI Cards US $251.04
|
 Digi 77000001 PC X 8 Port Multiport Serial Adapter US $250.00 |
Serial Communication Standards
Serial Communication Standards
All long-haul communications and most computer networks use serial connections, because the cost of cable and synchronization difficulties make parallel connections impractical. The most significant advantage is simpler wiring. Also, serial cables can be longer than parallel cables, because there is much less interaction (crosstalk) among the conductors in the cable. In this chapter, we will confine our consideration of serial communications to those connecting LANs to WANs.
Full Post:
Serial Communication Standards
Serial Communication Standards
The figure is a simple representation of a serial communication. Data is encapsulated by the communications protocol used by the sending router. The encapsulated frame is sent on a physical medium to the WAN. There are various ways to traverse the WAN, but the receiving router uses the same communications protocol to de-encapsulate the frame when it arrives.
There are many different serial communication standards, each one using a different signaling method. There are three key serial communication standards affecting LAN-to-WAN connections:
RS-232 - Most serial ports on personal computers conform to the RS-232C or newer RS-422 and RS-423 standards. Both 9-pin and 25-pin connectors are used. A serial port is a general-purpose interface that can be used for almost any type of device, including modems, mice, and printers. Many network devices use RJ-45 connectors that also conform to the RS-232 standard. The figure shows an example of an RS-232 connector.
V.35 - Typically used for modem-to-multiplexer communication, this ITU standard for high-speed, synchronous data exchange combines the bandwidth of several telephone circuits. In the U.S., V.35 is the interface standard used by most routers and DSUs that connect to T1 carriers. V.35 cables are high-speed serial assemblies designed to support higher data rates and connectivity between DTEs and DCEs over digital lines. There is more on DTEs and DCEs later in this section.
HSSI - A High-Speed Serial Interface (HSSI) supports transmission rates up to 52 Mb/s. Engineers use HSSI to connect routers on LANs with WANs over high-speed lines such as T3 lines. Engineers also use HSSI to provide high-speed connectivity between LANs, using Token Ring or Ethernet. HSSI is a DTE/DCE interface developed by Cisco Systems and T3plus Networking to address the need for high-speed communication over WAN links.
About the Author
http://www.mlbtv24.blogspot.com/
Docking Stations For Laptops Will Produce Increased Usefulness
Docking stations for laptops offer extra features for pc laptop computers. In fact, such devices make a notebook a lot more similar to a desktop than initially planned by design. If the notebook models are large enough with plenty of ports, docking stations for laptops are not necessary. It is with small-size laptops that one realizes the full practical utility of a docking stations. You can thus plug a mouse, a keyword, a printer or a second monitor in the docking stations and simply connect and disconnect the laptop from it.
Moreover low-tech computer users will hardly ever need docking stations for laptops. The functionality of these devices is high for home office and business office. Any peripheral can in fact be plugged into the docking stations and you access it without a direct connection to the computer. Usage flexibility, that is definitely the major advantage of docking stations for laptops even if they are not always justified by necessity. Some people consider it a waste of money to buy an additional device to plug the appliances, instead of connecting them all to the notebook ports. It all depends on how you perceive the device subjectively.
The lack of appliance compatibility also justifies the usage of docking stations for laptops. A relevant example is the connection of an old printer with an ultra-modern laptop. Lots of older printer designs still use the serial port connection that is no longer available on notebooks. With a docking stations you will be able to plug the appliance, whether with serial or USB cables and not need any special adapters for the operation. Another advantage of docking stations for laptops comes from the possibility of connecting secondary monitors with higher graphic features for superior video display.
Last but not least, quality in-built coolers represent another great quality of docking stations for laptops. Many laptops get heated, and this can be disastrous for the hardware. A device that cools the system and also increases the number of available ports becomes a great investment. Consider this aspect of a docking stations utility before deciding whether to buy one or not. As for the different kinds of available 'docks', you can check online and get access to hundreds of products. You'll certainly come across a good match for your computer.
Can I connect an External HDD to a Windows NT server using COM/Serial port?
I need to connect an external HDD to a computer running on Windows NT Server OS. There are no USB ports, just 2 COM/Serial ports and the external HDDs are with USB connections Could anyone tell me how I can connect the HDD to the pc?
No, you can't use the serial port. Even if you could, it would be dreadfully slow.
Compact PC offers AMD G-Series CPUs, quadruple serial ports (LinuxDevices)
ROV - Serial Port Communication
